Speaking in an interview with CNBC, DuckDuckGo CEO Gabe Weinberg
said that the company’s traffic has grown 600 percent over the
past two years. A variety of factors likely played a role in this
explosion of growth, but it is mainly attributable to the NSA’s
surveillance program, which was revealed two years ago, and Apple
adding it as a default search option with iOS 8 and Safari 7.1 on
the Mac.

Would be fascinating to see how usage would spike if Apple set it as the default search engine.